The present invention relates generally to chair constructions and, more specifically, to fixed seating for auditoriums, lecture halls, theaters, stadiums, and other fixed "public seating" applications.
Conventional fixed seating arrangements are often relatively complex in terms not only of construction but also in terms of assembly and installation. For example, there are known fixed seating constructions in which the seat and back components cannot be fully assembled until various internal adjustments are made at the time of installation. It will be readily appreciated that this kind of arrangement, with many parts and fasteners to be accounted for and assembled at the site, is costly and inefficient in terms of manufacturing, shipping and installation.
In various known fixed seating constructions, seat components also incorporate spring-type cushions which sag, squeak and which ultimately must be replaced. It is also often the case that the seat and back cushions are provided with internal, rigid frames which may cause wear points or even holes in the upholstery fabric covering the cushion frames.
The present invention provides a unique fixed seating construction which eliminates the above noted problems (as well as others) associated with conventional fixed seating arrangements.
Specific features of the invention include welded structural steel frame assemblies which provide improved strength over mechanically joined frames, and which easily accommodate installation on flat, sloped or stepped floors. Each frame assembly includes a standard, a floor mount plate, a seat support or mounting bracket, a back support or mounting bracket, and an arm rest support, all welded together at the manufacturing plant as a single unit. These welded frame assemblies do not fracture and break in the manner of conventional castings. The welded steel frame assemblies thus provide increased strength and durability while reducing the chances for injury which can occur with a sudden fracture or break.
The present invention also incorporates relatively rigid plastic shell type seat and back components which will accommodate (on their "back" or non-use sides) optional inserts of wood, laminate, fabric, etc. The components are comprised of unitized, blow molded shells, and the seat component is filled with foam (preferably rigid polyurethane) for added strength and rigidity. In addition, both have mounting assemblies which include steel mounting inserts fixed in place during the blow molding operation, as well as associated support bars which are fastened to the inserts in overlying relationship, prior to shipping. In this way, the seat and back components may be essentially finished at the manufacturing site and need only be mounted to and between a pair of adjacent frame assemblies (with a minimum number of fasteners) at the installation site, greatly reducing the time and cost of installation.
The use of plastic seat and back shells as described has additional advantages including: (1) integral coloring which won't chip or scratch like painted steel; (2) impact resistance; and (3) overall reductions in the number of parts, fabrication operations, maintenance and safety hazards.
The seat and back components are configured for "drop in" installation on the frame assemblies, as described in greater detail herein, which further simplifies installation by reducing the number of parts, fasteners, and installation tools required.
With respect to the back component, a pair of back support bars located on either side of the back component are provided with a pair of specially designed bolts which extend laterally away from the back component in the manner such that the lower pair of bolts may be drawn upwardly into downwardly opening grooves formed in the back mounting brackets, and the upper pair of bolts may then be rotated into bolt receiving recesses formed at the upper ends of the back mounting brackets and secured in place by a pair of impact modified, rigid nylon inserts.
Another feature of the invention relates to a unique hinge construction for the seat component which permits the above mentioned "drop-in" feature. The hinge, preferably of nylon construction, is a free floating unit which is self-lubricating and provides a clean, non-mechanical appearance.
More specifically, the hinge is designed to freely rotate on a hinge pin fixed to the seat support bracket of the frame assembly. The hinge is formed with a T-shaped slot adapted to receive a bolt head. The bolt head in this instance is part of another specially designed bolt which extends laterally out of the seat component and which may be dropped into the T-shaped slot. The hinge is also provided with a threaded aperture which is designed to threadably receive a bolt having a smooth distal shank portion which is receivable within an aperture provided in the seat mounting assembly. In this way, the hinge remains in free floating relationship relative to both the frame assembly seat mounting bracket and the seat component itself. Additional details with respect to the hinge construction are provided further herein.
The seat component also features an automatic counterweight return which brings the seat to an upright position when not in use. The counterweight is provided by a dense, particulate material loaded into the seat shell and properly located prior to the injection of the rigid polyurethane foam. This arrangement eliminates conventionally used springs (which are prone to fatigue failure) and essentially eliminates all maintenance of the counterweight automatic return arrangement.
Other features of the present invention relate to the use of adhesively secured foam cushions which provide increased comfort and which contain no moving parts such as serpentine coil springs which tend to deteriorate over time. The foam cushion feature also facilitates the application of upholstery fabric which in accordance with this invention, is set over the foam cushion (both seat and back) and pressed into a peripheral groove. A flexible female strip (preferably extruded polyethylene) is then pressed into the groove and the fabric is stapled through the strip to the underlying shell. A flexible male strip of similar material is then pushed into the female strip to thereby hide the staples and to otherwise provide a clean, streamlined and attractive appearance. The manner of application of the upholstery eliminates sewing and slip on constructions as well as seams and welts, thereby even further reducing costs and maintenance.
Thus, in accordance with one aspect of an exemplary embodiment of the invention, there is provided a chair comprising a frame including a pair of standards each including a seat mounting bracket and a back mounting bracket, each seat mounting bracket having a hinge pin; a seat component pivotally mounted on a pair of the hinge pins by means of a pair of hinges, each hinge comprising a main body portion freely rotatably mounted on one of the hinge pins, the main body portion also formed with a slot for receiving a bolt head of a first bolt threadably secured to the seat component.
In a related aspect, the invention provides a a chair comprising a frame including a pair of back mounting brackets and a pair of seat mounting brackets; a seat component mounted on and between the seat mounting brackets; and a back component mounted on the back mounting brackets wherein the back component includes an upper pair of laterally extending mounting pins and a lower pair of laterally extending mounting pins, the pair of back mounting brackets having surfaces for receiving the pair of upper and lower mounting pins in a substantial vertical load bearing relationship such that the back component is hung on the frame.
In another aspect, the invention provides a chair seat component comprising a one-piece plastic shell having upper and lower surfaces connected by a peripheral end wall, to thereby create an interior space; a pair of metal inserts molded in place within opposite portions of the peripheral end wall, the metal inserts each having at least one aperture therein for threadably receiving a seat mounting element therein; and wherein at least a portion of the interior space is filled with foam.
In still another aspect, the invention provides a chair back component comprising a one-piece plastic shell having front and back surfaces connected by a peripheral end wall, to thereby create an interior space; a pair of metal inserts molded in place within opposite portions of the peripheral end wall, the metal inserts each having at least one aperture therein for threadably receiving a back mounting element therein.
In still another aspect, the invention provides a chair component comprising a unitary shell having a groove extending about a peripheral portion thereof; a cushion secured to the shell within an area inside the groove; fabric applied over the cushion and secured within the groove; and an elongated strip pressed into the groove overlying the fabric.
The invention also relates to a method of forming a chair component comprising the steps of
a) blow molding a plastic shell having first and second surfaces connected by a peripheral end wall to thereby create an interior space, and wherein the first and second surfaces are welded to each other at a plurality of locations within an area defined by the peripheral end wall;
b) during step (a), blow molding in place a pair of metal inserts within opposite side portions of the peripheral end wall; and
c) injecting at least a portion of the interior space with foam.
It will thus be appreciated that the present invention provides a fixed seating construction where function, durability, economy and style are combined into a single product which provides the enumerated benefits and advantages. Additional objects and advantages will become apparent from the detailed description which follows.